Photographic processing device



Dec. 11, 1962 E. c. WOODCOCK ETAL 3,067,920

PHOTOGRAPHIC PROCESSING DEVICE Filed Nov. 28, 1960 w w W w W 4%) Q INVENTORS far ward Ceci/ Waoacocfi Jud/"e Pau/ (dun/e A 5 BY QRNEY United States Patent Ofiice 3,0fi7,92tl Patented Dec. 11, 1962 1 3,067,920 PHOTOGRAPHIC PROCESSING DEVICE Edward Cecil Woodcock, Pinner, England; Andre Paul Cauwe, Bruges, Belgium, and Joseph Antonius Debackere, Mortsel-Antwerp, Belgium, assignors to Gevaert Photo-Producten N.V., Mortsel, Belgium, :1 Belgian company Filed Nov. 28, 1960, Ser. No. 72,160 Claims priority, application Netherlands Apr. 1, 1960 8 Claims. (Cl. 226189) The present invention relates to photographic processing devices for film or paper sheets or strips. More particularly this invention relates to a photographic processing device wherein the adhering of the film or paper sheet or strip to some parts of the device, such as e.g. the guide rollers, is prevented and moreover wherein the deviation of the sheet or strip from its course between rollers is avoided.

Devices are already known for preventing the adhering of a film or paper sheet or strip to the rollers of photographic apparatus, and for preventing the deviation of said sheet or strip from its course. Devices provided with a scraper, a set of elastic blades or a number of curved pick off fingers resting on the surface of the rollers are commonly used for removing the film or paper sheets or strips from these rollers and for guiding them between 1 these rollers.

These devices show the disadvantage that they may give rise to the damaging of the rollers. Furthermore, very often the film or paper sheets or strips pass underneath the scraper, the blades, etc. and are wound on the rollers.

It is further known to use metal bars, flat guide members or arcuate blades which fit into specially shaped grooves provided in the rollers.

These devices show the disadvantage that they require the construction of special rollers and moreover the bars, guide members or arcuate blades have to be very accurately adjusted to fit into the respective concavities or grooves.

The application of all the above-mentioned devices in combination with an apparatus containing a set of rollers may cause the damaging of the guided film, in particular when the film being used, is emulsified at both sides, e.g. X-ray film.

It has now been found that in order to prevent the adherence of a film or paper sheet or strip to the rollers, and to avoid the deviation of said sheet or strip from its course between the rollers, in a simple way, thin wires may be placed over the rollers in such a way that these wires nowhere extend above the locus of the point of contact between the lower and the upper rollers.

According to the present invention the positioning of these wires may be executed by using rollers the surfaces of which are coated with an elastic layer in such a way that the wires are pressed into this elastic layer. Hereby a direct contact of the wires with the emulsion-layer of the guided film or sheet is avoided. The cross-section of the rollers may either be equal or different. The wires can be manufactured from synthetic material, steel, etc.

With reference to the accompanying drawings the present invention is illustrated by way of some examples mentioned hereinafter without limiting however the scope thereto.

FIG. 1 is an embodiment of the invention showing a crosswise position of the wires over the rollers;

FIG. 2 is a top view of the lower rollers according to FIG. 1;

FIG. 3 is another embodiment of the invention showing the saw-tooth wise formation of the wires over the rollers;

FIG. 4 is a top view of the lower rollers according to FIG. 3;

FIG. 5 is a cross-sectional view showing the wires contacting the resilient surface of the rollers.

Referring to FIG. 1 a set of guide rollers is shown for guiding the film or paper sheet or strip in a horizontal direction at the interior side of a drier. In this drier the film or paper is dried by means of a circulation of dry or/ and heated air, by infrared lamps, etc. The rollers are driven in the usual way by a chain, a belt, etc.

It is clear that owing to the cross-wise arrangement of the wires, in the present case nylon wires, the film or paper sheet or strip is prevented from winding up around a roller or to pass underneath any following roller. Due to the soft material coating of the rollers the wires are pressed into this coating thus preventing the direct contact with the guided film, and consequently to prevent the damage of the film.

The emulsion layer of the guided film or paper can be damaged either-in a direct or indirect way. In the first place, by a direct contact with a structural part of the device, whereby a sliding movement is effected on the emulsion layer. Next, indirectly in that the wires disturb the circulation of the dry air in the spaces between the successive roller pairs whereby air turbulences are formed between the wires and the film surface leaving longitudinal traces on the dried film; or otherwise also indirectly in that in those areas where the wires are pressed into the soft roller coating, the latter does not contact the film or paper, whereby a difference in drying speed occurs in respect to those areas where the film or paper is contacting the roller coating.

Owing to the small diameter of the wires said air-turbulences are very weak. The harmful effect caused by the wire lengths stretched on the roller coatings is neutralized by the force with which the rollers of each roller pair press against each other.

For reducing still more the indirect damaging of the film the wires are stretched longitudinally in an oblique position whereby the circulation of the air current is not always disturbed in the same longitudinal line of the material (FIG. 2).

In FIG. 3, showing the guide rollers of a drier, the wires are positioned saw-tooth wise over the rollers. According to this disposition the pressing of the wires on the roller coating is decreased since the wires are now more horizontally stretched over the rollers. For the execution of this disposition two cross-bars, parallel to each other and to the rollers, are positioned behind each roller thus allowing the stretching of the wires in the desired direction. In this case indirect damaging of the film is not avoided by stretching the wires obliquely as shown in FIG. 2, but by using a number of short wires, which are parallelly fitted in longitudinal direction and are not in direct line with each other (FIG. 4).

Of course the rollers shown in FIG. 3 can also be used in combination with obliquely positioned wires as shown in FIG. 2, and the rollers shown in FIG. 1 can be combined with the position of the wires shown in FIG. 4.

For ensuring the stretching of the wires, rubber strips, springs or similar means can be fitted in either of the foregoing devices. These devices can also successfully be used combined with developing or fixing apparatus, whereby indirect damaging of the film or paper sheet or strip does not even occur.

We claim:

1. A device for conveying sheet or strip material comprising in combination a plurality of roller pairs adapted to receive and advance said sheet or strip material between individual roller pairs during rotation of said rollers, a resilient surface on said rollers, flexible guide wires extending between adjacent roller pairs and tensioned over said rollers, said wires causing a local depression of the resilient surface of said rollers to be embedded therein at 3 the points of contact between the rollers of each roller pair.

2. A device for conveying sheet and strip material, comprising in combination a plurality of longitudinally spaced roller pairs, the rollers of each roller pair being mounted in vertically spaced relationship, said roller pairs advancing said sheet and strip material between successive roller pairs during rotation of said rollers, said rollers having a resilient surface, flexible guide wires extending between said longitudinally spaced roller pairs, said wires being tensioned to cause a local depression of the resilient surface of said rollers to be embedded therein at least at the points of contact between the individual rollers of each roller pair.

3. A device for conveying sheet or strip material according to claim 1 wherein said flexible wires do not extend above the resilient surface of said rollers at the points of contact between the rollers of individual roller pairs and said sheet and strip material advancing between said rollers.

4. A device as defined in claim 1 wherein the flexible wires extend between adjacent roller pairs alternately over and under corresponding rollers of each roller pair.

5. Device according to claim 4 wherein the flexible wires extending between adjacent roller pairs alternately over and under corresponding rollers of each roller pair are disposed obliquely to the direction of travel of the sheet and strip material.

6. Device according to claim 1 wherein said flexible wires are disposed between spaced roller pairs in sections extending in the direction of travel of the sheet and strip material and displaced transversely relative to adjacent sections.

7. Device according to claim 6 wherein wire tensioning means are disposed adjacent corresponding rollers of each roller pair.

8. Device as defined in claim 1 wherein said flexible wires are skewed relative to the direction of travel of said sheet material whereby each section of said material has transversely substantially the same amount of contact with said flexible wires.

References Cited in thefile of this patent UNITED STATES PATENTS 2,037,806 Little Apr. 21, 1936 2,338,770 Leguillon Jan. 11, 1944 2,596,625 Vergobbi May 13, 1952 2,828,123 Guillemette Mar. 25, 1958 

